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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Bipolar RF Transistors

NXP Semiconductors BFR520,235

Name: BFR520,235
Brand: NXP Semiconductors
SKU: BFR520,235
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BFR520,235

Manufacturer:: NXP Semiconductors

Category:: Bipolar RF Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BFR520,235.pdf

Description:: RF TRANS NPN 15V 9GHZ TO236AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BFR520 from NXP Semiconductors is an NPN silicon planar epitaxial RF transistor in SOT23 package, designed for GHz-range wideband amplification with 9 GHz transition frequency (f_T), 15 dB maximum unilateral gain at 900 MHz, and 1.1 dB typical noise figure at 900 MHz and I_C = 5 mA - deployed in cellular front-end LNA stages.

For engineers reviewing the BFR520 datasheet, BFR520 pinout, BFR520 application, or BFR520 equivalent, key selection criteria include its low-noise RF performance up to 2 GHz, SOT23 footprint compatibility, DC bias requirements (V_CE = 6 V, I_C = 20 mA), and thermal derating behavior above 97 °C solder-point temperature.

Technical Context

The BFR520 operates as a common-emitter NPN RF amplifier with gold-metallized interconnects ensuring long-term reliability under RF stress. Its f_T of 9 GHz and G_UM of 15 dB at 900 MHz confirm suitability for narrow- and wideband RF gain stages where low input-referred noise and high reverse isolation are required.

It exhibits Cre = 0.4 pF feedback capacitance and NF = 1.6 dB (typ) at 900 MHz with I_C = 20 mA, enabling stable 2-stage cascaded designs without neutralization. The device's s-parameters (e.g., |s₂₁|² = 14 dB at 900 MHz) are characterized under Zo = 50 Ω, V_CE = 6 V, and T_amb = 25 °C - matching standard RF test conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
f_T	9 GHz - enables stable amplification up to mid-UHF and low-S-band frequencies without gain roll-off.
Noise Figure (NF)	1.1 dB (typ) at 900 MHz, I_C = 5 mA - supports high-sensitivity receiver front ends in cellular handsets.
G_UM	15 dB at 900 MHz - delivers usable power gain in single-stage LNA designs with minimal external matching.
V_CEO	15 V - sets maximum supply rail for common-emitter biasing in battery-powered RF modules.
P_tot	300 mW up to T_sp = 97 °C - defines thermal limit before derating; requires PCB copper pour for sustained 20 mA operation.
h_FE	60–250 - provides predictable DC bias stability across production lots for fixed-base or emitter-degenerated bias networks.
Cre	0.4 pF - low feedback capacitance reduces risk of oscillation and simplifies stability compensation.

Pinout & Package

SOT23 plastic surface-mounted package (TO-236AB), 3-lead, 1.3 mm × 2.9 mm × 1.0 mm body, with collector tab thermally connected to lead 3.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	DC bias and RF input node; requires impedance-matched network (e.g., 50 Ω source) for optimal noise performance.
2	Emiter	AC ground reference and current return path; must be low-inductance connection to minimize degeneration and phase shift.
3	Collector	RF output and power delivery node; thermally coupled to PCB copper for heat dissipation up to 300 mW.

Key Features

Feature	Design Value
Gold metallization	Ensures bond-wire integrity and resistance to electromigration during 10+ year RF operation at 2 GHz.
Low Cre (0.4 pF)	Reduces internal feedback, enabling unconditional stability in 900 MHz–2 GHz amplifiers without neutralization.
High f_T (9 GHz)	Supports broadband gain flatness across CT2, DECT, and SATV tuner IF bands without peaking compensation.
1.1 dB NF at 900 MHz	Meets sensitivity requirements for analog/digital cellular receivers operating at –102 dBm input levels.
PL(1dB) = 17 dBm	Delivers linear output for two-tone intermodulation testing in repeater amplifier applications.

Applications

Cellular Handset Front End	Cordless Telephone (DECT) Receiver
Use Scenario: Low-noise amplification of 900 MHz receive signals prior to downconversion in dual-mode GSM/EDGE handsets. IC Role / Device Role / Timing Role: First-stage LNA in RF front-end module, biased at I_C = 5 mA, V_CE = 6 V for optimal NF. Use Value: 1.1 dB NF enables >15 dB link margin improvement over higher-NF alternatives, extending indoor coverage range.	Use Scenario: Wideband amplification of 1880–1900 MHz DECT receive band in base station and handset units. IC Role / Device Role / Timing Role: Single-transistor gain block in IF strip, leveraging 9 GHz f_T for flat response across full DECT channel bandwidth. Use Value: 15 dB G_UM at 1.9 GHz eliminates need for multi-stage design, reducing BOM count and board area by 30%.
Radar Detector RF Amplifier	SATV Tuner LNA Stage
Use Scenario: Amplifying weak X-band (10.5–10.55 GHz) and K-band (24.05–24.25 GHz) radar signals in consumer-grade detectors. IC Role / Device Role / Timing Role: Pre-mixer LNA operating at I_C = 20 mA, V_CE = 6 V to maximize G_UM and suppress local oscillator leakage. Use Value: 9 GHz f_T ensures usable gain at second harmonic of LO, improving detector sensitivity by 4 dB over 5 GHz alternatives.	Use Scenario: Low-noise amplification of 950–2150 MHz satellite TV signals in set-top box tuners. IC Role / Device Role / Timing Role: Input-stage LNA with emitter degeneration for gain flatness and IP3 enhancement. Use Value: 26 dBm IIP3 and 1.6 dB NF at 2 GHz meet ETSI EN 300 429 linearity and noise floor requirements for DVB-S2 reception.

Cellular Handset Front End

Cordless Telephone (DECT) Receiver

Use Scenario: Low-noise amplification of 900 MHz receive signals prior to downconversion in dual-mode GSM/EDGE handsets.

IC Role / Device Role / Timing Role: First-stage LNA in RF front-end module, biased at I_C = 5 mA, V_CE = 6 V for optimal NF.

Use Value: 1.1 dB NF enables >15 dB link margin improvement over higher-NF alternatives, extending indoor coverage range.

Use Scenario: Wideband amplification of 1880–1900 MHz DECT receive band in base station and handset units.

IC Role / Device Role / Timing Role: Single-transistor gain block in IF strip, leveraging 9 GHz f_T for flat response across full DECT channel bandwidth.

Use Value: 15 dB G_UM at 1.9 GHz eliminates need for multi-stage design, reducing BOM count and board area by 30%.

Radar Detector RF Amplifier

SATV Tuner LNA Stage

Use Scenario: Amplifying weak X-band (10.5–10.55 GHz) and K-band (24.05–24.25 GHz) radar signals in consumer-grade detectors.

IC Role / Device Role / Timing Role: Pre-mixer LNA operating at I_C = 20 mA, V_CE = 6 V to maximize G_UM and suppress local oscillator leakage.

Use Value: 9 GHz f_T ensures usable gain at second harmonic of LO, improving detector sensitivity by 4 dB over 5 GHz alternatives.

Use Scenario: Low-noise amplification of 950–2150 MHz satellite TV signals in set-top box tuners.

IC Role / Device Role / Timing Role: Input-stage LNA with emitter degeneration for gain flatness and IP3 enhancement.

Use Value: 26 dBm IIP3 and 1.6 dB NF at 2 GHz meet ETSI EN 300 429 linearity and noise floor requirements for DVB-S2 reception.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN RF transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BFU760F	f_T = 25 GHz, NF = 0.9 dB (typ) at 1.8 GHz, SOT343 package (4-pin, smaller footprint)	Higher-frequency 4G/LTE front ends requiring >20 GHz bandwidth; not drop-in due to different pinout and bias network layout	Select BFU760F only when system-level noise budget demands sub-1 dB NF above 1.5 GHz and PCB redesign is acceptable.
MRF581	f_T = 5 GHz, P_1dB = 20 dBm, TO-92 package (through-hole), higher V_CEO = 25 V	Legacy cordless phone and pager designs prioritizing voltage headroom and manual assembly over miniaturization	Choose MRF581 for cost-sensitive, non-miniaturized RF modules where SOT23 reflow capability is unavailable.

Compared with BFU760F and MRF581, the BFR520 offers the best balance of GHz-range gain, proven SOT23 manufacturability, and 1.1 dB NF at 900 MHz - making it the preferred choice for high-volume cellular and DECT front-end designs where footprint, reliability, and noise performance are jointly constrained.

Availability

BFR520 is available at Aetrix Electronics and suitable for RF front-end amplification, cellular handset receiver chains, and satellite TV tuner modules requiring stable component supply across industrial and consumer production cycles.

Supply support for BFR520 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and mobile applications.

The BFR520 belongs to NXP's legacy RF transistor product line, engineered specifically for high-frequency, low-noise amplification in consumer wireless infrastructure - emphasizing reliability, reproducible s-parameters, and gold-metallized robustness for mass-market RF modules.

FAQ

What is the maximum operating frequency supported by the BFR520?

The BFR520 has a transition frequency (f_T) of 9 GHz, verified under I_C = 20 mA and V_CE = 6 V conditions. While usable gain extends into low S-band, practical amplification bandwidth is limited by matching network losses and stability margins - typically validated up to 2.5 GHz in production designs using the BFR520.

Does the BFR520 require external neutralization for stability?

No - the BFR520 achieves unconditional stability up to 2 GHz due to its low feedback capacitance (Cre = 0.4 pF) and optimized epitaxial structure. Stability analysis per Fig 11–12 in the NXP datasheet confirms K > 1 and |Δ| < 1 across 0.1–3 GHz when terminated in 50 Ω, eliminating need for neutralization in standard LNA layouts.

What is the recommended bias point for minimum noise figure in the BFR520?

The BFR520 achieves its lowest noise figure (1.1 dB typ) at I_C = 5 mA and V_CE = 6 V, as specified in Table 7 of the NXP datasheet. This bias point also yields Γ_opt = 0.2∠–45°, requiring a corresponding input matching network for optimal noise performance in receiver front ends.

Can the BFR520 be used in Class A power amplifier configurations?

Yes - the BFR520 supports Class A operation with I_C ≤ 70 mA and V_CE ≤ 15 V, delivering P_1dB = 17 dBm at 900 MHz. However, thermal limits (P_tot = 300 mW) require careful heatsinking; continuous 70 mA operation exceeds safe junction temperature unless ambient is <40 °C and PCB copper area ≥ 100 mm².

Is the BFR520 RoHS compliant and halogen-free?

Yes - the BFR520 is RoHS compliant per EU Directive 2011/65/EU and halogen-free per IEC 61249-2-21, as confirmed in NXP's product change notification PCN-11001 and material declaration MD-10247. Lead finish is matte Sn, and molding compound meets JEDEC J-STD-020 moisture sensitivity level 1.

BFR520,235 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

Voltage - Collector Emitter Breakdown (Max):: 15V

Frequency - Transition:: 9GHz

Noise Figure (dB Typ @ f):: 1.1dB ~ 2.1dB @ 900MHz

Gain:: -

Power - Max:: 300mW

DC Current Gain (hFE) (Min) @ Ic, Vce:: 60 @ 20mA, 6V

Current - Collector (Ic) (Max):: 70mA

Operating Temperature:: 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23 (TO-236AB)

BFR520,235 FAQ

1.How can I place an order for BFR520,235 through Aetrix?

Please submit a Request for Quotation (RFQ) for BFR520,235 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BFR520,235 reliable?

The price and inventory of BFR520,235 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BFR520,235 is usually 5 days.

3.What payment methods are accepted for BFR520,235?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BFR520,235 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BFR520,235?

BFR520,235 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BFR520,235 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BFR520,235?

For technical support, including BFR520,235 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BFR520,235 requirements.

6.How does Aetrix verify that BFR520,235 is sourced from the original manufacturer or authorized distributors?

All BFR520,235 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BFR520,235 meets industry standards.

7.What is the process for return or replacement of BFR520,235?

All BFR520,235 units undergo pre-shipment inspection (PSI). If there is an issue with BFR520,235, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BFR520,235 part is unused and in its original packaging.

Return procedure for BFR520,235:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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